/*
 * 代号：凤凰
 * http://www.jphenix.org
 * 2014-06-10
 * V4.0
 */
package com.jphenix.clazz;

import com.jphenix.standard.docs.ClassInfo;

/**
 * A collection of static methods for reading and writing a byte array.
 * @author mabg
 */
@ClassInfo({"2014-06-10 19:46","A collection of static methods for reading and writing a byte array"})
public class ByteArray {
    
    /**
     * Reads an unsigned 16bit integer at the index.
     */
    public static int readU16bit(byte[] code, int index) {
        return ((code[index] & 0xff) << 8) | (code[index + 1] & 0xff);
    }

    /**
     * Reads a signed 16bit integer at the index.
     */
    public static int readS16bit(byte[] code, int index) {
        return (code[index] << 8) | (code[index + 1] & 0xff);
    }

    /**
     * Reads a 32bit integer at the index.
     */
    public static int read32bit(byte[] code, int index) {
        return (code[index] << 24) | ((code[index + 1] & 0xff) << 16)
               | ((code[index + 2] & 0xff) << 8) | (code[index + 3] & 0xff);
    }


    /**
     * Copies a 32bit integer.
     *
     * @param src       the source byte array.
     * @param isrc      the index into the source byte array.
     * @param dest      the destination byte array.
     * @param idest     the index into the destination byte array.
     */
    static void copy32bit(byte[] src, int isrc, byte[] dest, int idest) {
        dest[idest] = src[isrc];
        dest[idest + 1] = src[isrc + 1];
        dest[idest + 2] = src[isrc + 2];
        dest[idest + 3] = src[isrc + 3];
    }
}
